Similar to buildings that require a stable foundation to support the building for the duration of the life of the building, construction projects that cover an area of ground require a stable foundation. Construction projects that fit into this class of projects include roads, airport runways, warehouses, and earth works such as levees, dams, and landscapes having steep grades. Other construction projects have this need as well. A subsidence of the earth beneath all of these types of projects causes immense damage and can be catastrophic to the point of risking lives, so the stable base is a must.
To establish this stable base at large area construction sites, the ground is compacted to form a layer of solid, stable, earth to support the structure over the life of the structure. This compaction may take multiple iterations where compacting equipment passes over an area to compact the soil. In some cases, soil in place is compacted and then additional soil is brought to the location and compacted on top of the original, compacted soil. For levees and dams that require a build-up of earth, the process necessarily requires high repetitions of the process of adding soil and compacting. In many cases, the added soil has specific characteristics for specific properties. Clay, for example, is frequently used as a constituent ingredient for its properties.
The soil compaction process is highly sensitive to the moisture content level in the soil. If the moisture content is too high, the compaction process does not work. This can essentially halt major construction projects until the issue is addressed which results in huge costs in time and money. There currently are methods for adjusting, i.e. removing, moisture from soil at construction sites. One method is removing earth from a location and spreading it for drying. Once the spread earth is sufficiently dry, it is moved back to the location and compacted. Another method is mixing in other components such as lime, etc. to reduce the moisture content. The different methods are not mutually exclusive. Once the moisture content of the soil is tested and meets the required low moisture content, the compaction process can begin.